JP2010202033A - Stabilizer device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which does not require a complicated manufacturing method and can prevent a phenomenon in which abnormal noise and instability of effectiveness are gradually increased. <P>SOLUTION: In this stabilizer device, a bush 20 which is bridged between the outer peripheral surface of a cylindrical thermoplastic plastic 21 which is affixed to the outer periphery of a stabilizer bar 100 and the inner peripheral surface of a bracket 32, has four gaps therein, and is formed of four blocks 20a is formed using a thermoplastic elastomer. The bush 20 formed using the thermoplastic elastomer is formed by an injection molding using a melted thermoplastic elastomer. The bush 20 is fused to the thermoplastic plastic 21 which is affixed to the stabilizer bar 100, and also fused to the bracket 32. Consequently, the bush 20 and the bracket 32 are formed integrally with the stabilizer bar 100. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stabilizer device for a vehicle.

  A stabilizer device is known as a component that relieves the inclination of the vehicle body due to rolling deviation during corner steering of an automobile and the inclination of the vehicle body due to road surface unevenness. As a structure for attaching the stabilizer bar of the stabilizer device to the vehicle body, a structure in which a rubber bush attached to the stabilizer bar is held by a bracket and the bracket is attached to the vehicle body is known. This technique is described in, for example, Patent Documents 1 to 3.

  A method of directly bonding a bracket and a stabilizer bar is described in Patent Document 4, for example. Further, for example, Patent Document 5 describes a method in which a bracket and a bush are first vulcanized and bonded, and then bonded to a stabilizer bar using an adhesive. In addition, for example, Patent Document 6 describes a method of configuring a member functioning as a bush from a single thermoplastic resin material.

Japanese Utility Model Publication No. 1-60910 JP 2000-142068 A JP 2008-168756 A US Publication No. 2005 / 026393A1 JP 2006-264435 A JP 2000-233626 A

  In the fixing method using the conventional rubber bush described above, abnormal noise accompanied by rubbing with the rubber bush due to the twist of the stabilizer around the stabilizer shaft, and rubbing with the bush due to misalignment of the stabilizer bar in the stabilizer axial direction. The instability of sound and stabilizer effectiveness becomes a problem.

  According to the analysis of the present inventors, there is a gap between these rubbing surfaces, and the stabilizer bar causes a stick-slip phenomenon with the bush each time it is twisted. It has been confirmed that the instability gradually increases.

  The structure that is attached to the stabilizer bar by pressing the bush configured as a single unit with the bracket relies on frictional force, so a gap occurs on the rubbing surface mentioned above, and abnormal noise and instability of the effect as wear progresses In principle, it is difficult to prevent the phenomenon of increasing gradually.

  In addition, the method of bonding with an adhesive is troublesome in the construction method, and must use an organic solvent-based primer or adhesive, so that a volatile organic solvent is used, so that the working environment is also good. I can't say that. In addition, experiments have shown that even if a strong adhesive is used, it is difficult to suppress peeling of the adhesive interface.

  In such a background, an object of the present invention is to provide a technique that does not require a complicated construction method and can prevent a phenomenon in which abnormal noise or instability of effects gradually increases.

  The invention according to claim 1 is a stabilizer bar, a cylindrical thermoplastic plastic fixed to an outer periphery of the stabilizer bar, a bracket fixed to a vehicle body, an outer peripheral surface of the plastic, and an inner surface of the bracket And a bush made of a thermoplastic elastomer fixed to the plastic and the bracket by thermal welding.

  According to the first aspect of the present invention, the thermoplastic plastic fixed to the outer periphery of the stabilizer bar and the bush are firmly fixed by the fixing function by the thermal welding of the thermoplastic elastomer. Further, the bush is firmly fixed by thermal welding of the bracket and the thermoplastic elastomer. Unlike the fixing structure using friction or adhesion, the fixing by this welding uses the property of being integrated with the contacted member in the process of solidifying the thermoplastic elastomer constituting the bush from a molten state. For this reason, in principle, peeling at the interface between the bush and the plastic on the outer periphery of the stabilizer bar and at the interface between the bush and the bracket is unlikely to occur.

  In particular, in the welding of thermoplastics and thermoplastic elastomers, a part of the surface of the thermoplastic is melted or softened by the heat conducted from the molten thermoplastic elastomer, so that both constituent materials are mixed at the interface between the two. A mixed layer is formed, resulting in a strong integrated structure. For this reason, the structure where peeling of the interface between both is difficult is realized.

  In addition, since the bushes with gaps formed at two or more locations are fixed, the stabilizer bar rotates when the stabilizer bar rotates relative to its axis even when the bush is fixed to the stabilizer bar and bracket. As a result, the bush tends to deform. Therefore, the load applied to the bush itself or the interface between the bush and the plastic and the interface between the bush and the bracket can be reduced, and breakage of the bush and separation at the interface can be prevented. Furthermore, the stabilizer device can be reduced in weight, and the manufacturing cost can be reduced.

  The location where the air gap is formed may be a location where the shape of the bush is equal or a location where the shape is not uniform. In addition, two or more locations such as three or four or more locations are preferred for bushing manufacture or assembly reasons.

  According to a second aspect of the present invention, in the first aspect of the invention, when the stabilizer bar is rotated relative to the bracket around the axis thereof, the bush has a rotation angle of the rotation. When the material is broken at 60 ° or more and the material breakage occurs, peeling failure at the interface between the plastic and the bracket of the bush does not occur.

  According to the invention described in claim 2, in the stage before the thermoplastic elastomer constituting the bush is broken, peeling at the interface between the bush and the plastic on the outer periphery of the stabilizer bar, and further, between the bush and the bracket. No peeling at the interface. Thereby, generation | occurrence | production of the noise by the peeling in these interfaces arising, and the fall of the effect of a stabilizer are suppressed.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the coefficient of dynamic friction of the faces facing each other with the gap interposed therebetween is 0.4 or less.

  According to the third aspect of the present invention, when the stabilizer bar rotates relatively around its axis, the bush is deformed as the stabilizer bar rotates, and the surfaces facing each other with the gap in between are brought into contact with each other to generate frictional force. Will occur. At that time, if the dynamic friction coefficient of the facing surfaces is 0.4 or less, the frictional force of the facing surfaces does not hinder the rotation of the stabilizer bar. Therefore, it is possible to prevent the bush from restricting the rotational operation of the stabilizer bar, the stabilizer device can exhibit the performance intended for the predetermined design, and the reliability of the stabilizer device can be enhanced.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the thermoplastic plastic is a crystalline thermoplastic plastic.

  According to the fourth aspect of the present invention, it is possible to firmly fix the stabilizer to the stabilizer bar by utilizing the property that the crystallinity at the time of cooling and solidification of the crystalline thermoplastic plastic increases and shrinks at the same time. As crystalline thermoplastics, PE (polyethylene), polymethylpente, polybutene, crystalline polybutadiene, PET (polyethylene terephthalate), POM (polyacetal), PC (polycarbonate), polyphenyl ether, PBT (polybutylene terephthalate) , U-PE (ultra high molecular weight polyethylene), polyacetal (polyoxymethylene), polyamide, polycarbonate, polyphenylene ether, polyarylate (U polymer), polyethersulfone, polyimide, polyamideimide, polyphenylene sulfide, polyoxybenzoyl, polyether Ether ketone, polyether imide, and other liquid crystal polyesters can be used.

  According to a fifth aspect of the present invention, there is provided a step of disposing a bracket having a predetermined length in the axial direction in a mold and a stabilizer bar having a cylindrical thermoplastic plastic fixed to the outer periphery thereof, and the mold. The molten thermoplastic elastomer is injected into the inside and thermally welded to the bracket, and is thermally welded to the plastic, and is bridged between the outer peripheral surface of the plastic and the inner side surface of the bracket to form a gap at two or more locations. And a step of forming a bush to be formed by an injection molding method.

  According to the invention described in claim 5, there is provided a method of manufacturing a stabilizer device using the invention described in claim 1.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, when the stabilizer bar is rotated relative to the bracket relative to its axis, the bush has a rotation angle of the rotation. When the material is broken at 60 ° or more and the material breakage occurs, peeling failure at the interface between the plastic and the bracket of the bush does not occur.

  The invention described in claim 7 is characterized in that, in the invention described in claim 5 or 6, the coefficient of dynamic friction of the faces facing each other with the gap interposed therebetween is set to 0.4 or less.

  The invention according to claim 8 is the invention according to any one of claims 5 to 7, wherein the thermoplastic plastic is a crystalline thermoplastic plastic, and the thermoplastic plastic is cooled by cooling. The method further comprises a step of fixing the thermoplastic plastic to the stabilizer bar by shrinking while improving the crystallinity of the plastic.

  According to the invention described in claim 8, by utilizing the heat shrinkability at the time of cooling and solidifying the thermoplastic crystalline plastic, the plastic can be more firmly fixed to the stabilizer bar. A structure in which the generation of noise and instability in the structural part attached to the vehicle body is further suppressed can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which does not require a complicated construction method and can prevent the phenomenon which abnormal noise and the instability of an effect increase gradually is provided.

It is a schematic diagram which shows the stabilizer apparatus of the state attached to the vehicle. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is process drawing which shows the manufacturing process of the attaching part of FIG. It is process drawing which shows the manufacturing process of the attaching part of FIG. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is sectional drawing which shows the outline | summary of the attaching part which attaches the stabilizer apparatus to the vehicle body. It is sectional drawing which shows the outline | summary of the conventional attaching part. It is sectional drawing which shows the outline | summary of the conventional attaching part. It is sectional drawing which shows the outline | summary of the conventional attaching part.

(Stabilizer device: Overall overview)
Hereinafter, an example of a stabilizer device using the present invention will be described. First, a state where the stabilizer device is attached to the vehicle body will be briefly described. FIG. 1 is a schematic diagram showing a stabilizer device and the surrounding structure. FIG. 1 shows a state in which the stabilizer device 1 is attached to the front wheel side of the vehicle. In this example, the stabilizer device 1 includes a stabilizer bar 100 bent in a substantially U-shape. A stabilizer link 11, which is a rod-like member, is attached to one end of the stabilizer bar 100, and the other end of the stabilizer link 11 is fixed to the arm 13 of the suspension device 3 via a movable joint 12. The lower end of the arm 13 is fixed to a bearing that supports the shaft of the tire 2, and the upper end of the arm 13 is connected to a cylinder 14 that can be displaced relative to the arm 13 and elastically. The cylinder 14 is a part of the suspension device 3 and has a structure in which the weight of a vehicle body (not shown) is added to the cylinder 14.

  Although not shown, the arm 13 and the cylinder 14 are coupled via a coil spring, and an elastic coupling mechanism between them is realized. Although not shown, the other end of the stabilizer bar 100 is also connected to the suspension 5, and the suspension 5 supports the weight of the vehicle body applied to the tire 4. The stabilizer bar 100 is attached to the chassis (frame structure) of the vehicle body (not shown) using the attachment portions 30 and 31.

  The attachment part 31 is demonstrated easily. FIG. 2 is a cross-sectional view showing a state where the attachment portion 31 is viewed from the positive direction of the X axis. FIG. 2 shows a cross-sectional structure of the attachment portion 31 of FIG. As shown in FIGS. 1 and 2, a cylindrical sleeve 21 made of injection-moldable thermoplastic plastic is fixed to the outer peripheral surface of the stabilizer bar 100.

  As a thermoplastic plastic material constituting the cylindrical sleeve 21, if it is general-purpose plastic, ABS, PET (polyethylene terephthalate), PP (polypropylene), PS (polystyrene), PMMA (acrylic), PE (polyethylene), PVC ( PVC) can be used. For engineering plastics, PA (polyamide), POM (polyacetal), PC (polycarbonate), modified PPO, PBT (polybutylene terephthalate), U-PE (ultra high molecular weight polyethylene), PVDF (polyvinylidene fluoride) are used. be able to. For super engineering plastics, PSU (polysulfone), PES (polyethersulfone), PPS (polyphenylene sulfide), PAR (polyarylate), PAI (polyamideimide), PEI (polyetherimide), PEEK (polyether) Ether ketone), LCP (liquid crystal polymer), and polytetrafluoroethylene can be used. In addition, thermosetting resins such as phenol, urea, melamine, unsaturated polyester, epoxy, silicone, and polyurethane can also be used. Of these, crystalline thermoplastics (typically polypropylene) are most preferred.

  The length of the cylindrical sleeve 21 in the axial direction may be the same as the length of the bracket 32 in the axial direction, may be short, or may be long. A bush 20 made of thermoplastic elastomer is fixed to the outer peripheral surface of the cylindrical sleeve 21 in a heat-welded state, and a metal bracket provided with a flange 33 on the outer periphery of the bush 20 made of thermoplastic elastomer. 32 is fixed. The bush 20 and the bracket 32 are also fixed by thermal welding of the thermoplastic elastomer constituting the bush 20 to the bracket 32. The flange 33 is formed with a bolt hole 34 for attaching the bracket 32 to a vehicle body structure not shown. Note that the attachment portion 30 has the same structure as the attachment portion 31.

  The bush 20 is bridged between the outer peripheral surface of the cylindrical sleeve 21 and the inner surface of the bracket 32, and is composed of four blocks 20a. The bush 20 is formed with four blocks 20a with gaps formed at four locations. Adjacent blocks 20a are connected on the cylindrical sleeve 21 side. That is, the bush 61 is thermally welded to the entire outer peripheral surface of the cylindrical sleeve 21 in the range where injection molding is performed. The facing surfaces between adjacent blocks 20a across the gap are formed so that the dynamic friction coefficient (μ) is 0.4 or less.

  The boundary between the block 20a and the block 20a is the distance between the surfaces of the cylindrical sleeve 21 and the bracket 32 that face each other, and the distance between an arbitrary point on the side surface of the bracket 32 and the surface of the cylindrical sleeve 21. The thickness of the bush 20 is less than 30% to 30% or more.

  The thermoplastic elastomer that can be used is, on the condition that it can be injection-molded, specifically, olefin (TPO), styrene butadiene styrene (SBS), styrene ethylene butadiene styrene (SEBS), styrene ethylene butadiene styrene. (SEBS), polyester (TPEE), polyurethane (TPU), vinyl chloride (TPVC), and polyamide (TPAE) can be used.

  Among these, olefin (TPO) is preferable because it can set a wide range of hardness, flexibility and mechanical properties, and is excellent in weather resistance and cold heat resistance. The mechanical properties of each material system are as follows: hardness (JISA hardness) of 40 to 80, tensile breaking strength of 5 to 50 MPa, tensile modulus of elasticity of 1 to 20 MPa, tensile elongation of 150% or more, and compression set of 70 ° C. -It is preferable that it is 50% or less by 25% compression for 22 hours.

  The physical properties of the members that make up these bushings are designed from the weight and center of gravity of the vehicle, depending on the type of vehicle used, and the specifications of the stabilizer bar (for example, the main specification elements are the bar diameter, Whether it is real or hollow, etc.).

(Manufacturing method of mounting part)
3 and 4 are process cross-sectional views illustrating an example of a method for manufacturing the attachment portion. FIG. 3A shows the mold 131 in a state where the bracket 32 and the stabilizer bar 100 are arranged. On the front side and the heel side of the mold 131, a front and rear pressing mold (not shown) in which a hole through which the stabilizer bar 100 passes is formed is fixed in contact with the mold 131 from the front and rear. The stabilizer bar 100 is held at the illustrated position by the front and rear pressing molds (not shown). A part 133 of the front and rear pressing mold for forming a gap in the bush 20 is inserted into the bracket 32 from the axial direction.

  The manufacturing process will be described below. First, a roughening process is performed on the portion of the stabilizer bar 100 where the cylindrical sleeve 21 contacts and the portion of the bracket 32 where the bush 20 contacts. The roughening treatment is performed by blasting such as shot peening, discharge treatment by corona discharge or plasma discharge, cleaning treatment with an organic solvent such as acetone or xylene, and treatment with acid.

  In addition, the current stabilizer bar is standard rod shape with a round cross section, but the range of the fixed portion of the sleeve is a polygonal shape or flat cross section shape to suppress lateral slip slip in the axial direction and rotational slip slip around the shaft. You can also.

  In order to improve the wettability of the thermoplastic elastomer and further increase the welding strength, it is preferable to further subject the roughened portions to a surface modification treatment by hot melt. This treatment can be performed by using a commercially available olefin-based or urethane-based hot melt, which has been formed into a film in advance, or by dissolving it in an adherend in advance, or by dissolving it in a volatile solvent. Although the method of apply | coating and drying to a to-be-adhered body can be employ | adopted, film-like welding is preferable from the point of environmental protection.

  When the above-described ground processing is completed, the bracket 32 is placed inside the mold 131 as shown in FIG. On the other hand, the cylindrical sleeve 21 is fixed to the stabilizer bar 100 that has undergone the above-described ground processing. In this operation, first, the cylindrical sleeve 21 is manufactured from PP (polypropylene) which is a thermoplastic thermoplastic having crystallinity. The cylindrical sleeve 21 is directly molded on the outer periphery of the stabilizer bar 100 by injection molding. At this time, at the time of cooling after injection molding, the crystallinity of polypropylene increases, and contraction in the direction of the axial center occurs. Thereby, the cylindrical sleeve 21 is welded to the stabilizer bar 100 and firmly fixed by the contraction force. At this time, the polypropylene material enters inside the rough irregularities formed on the outer periphery of the stabilizer bar 100, and the anchoring effect is promoted by the anchor effect.

  After the cylindrical sleeve 21 is fixed to the stabilizer bar 100, the stabilizer bar 100 is fixed in the mold 131 with the positional relationship shown in FIG. Next, the upper presser mold 132 is disposed on the upper side, and a space 134 is formed in the mold (FIG. 3B). The upper presser mold 132 is provided with an injection hole 135 for injecting the thermoplastic elastomer fluidized by heating into the space 134. Reference numeral 136 denotes an air vent hole for injection molding.

  When the state shown in FIG. 3B is obtained, the thermoplastic elastomer melted by heating is injected from the injection hole 135 into the space 134 and injection molding is performed. At this time, the thermoplastic elastomer is welded to the outer peripheral surface of the cylindrical sleeve 21 and the inner surface of the bracket 32.

  According to this process, since the inner surface of the bracket 32 is roughened and countless minute irregularities are formed, the molten thermoplastic elastomer enters the minute irregularities. For this reason, in the process in which the thermoplastic elastomer is solidified, the thermoplastic elastomer and the bracket 32 are bonded and integrated with each other.

  In addition, when the molten thermoplastic elastomer is injected into the space 134, the surface of the cylindrical sleeve 21 made of polypropyne is melted or softened by heat, and a mixed layer between the polypropylene material and the thermoplastic elastomer is formed. It is formed, and an adhering state with higher integrity than simple welding can be obtained.

  In this way, the state shown in FIG. 4 is obtained. In this state, the bush 20 made of the solidified thermoplastic elastomer is welded to the bracket 32 and is fixed to the stabilizer bar 100 via the cylindrical sleeve 21. When the state shown in FIG. 4 is obtained, the state shown in FIG. 2 is obtained by removing the mold.

  As described above, in the present embodiment, the bush 20 interposed between the stabilizer bar 100 and the bracket 32 to which the cylindrical sleeve 21 composed of the cylindrical thermoplastic plastic (polypropylene) is fixed is made of the thermoplastic elastomer. Constitute. The bush 20 made of this thermoplastic elastomer is formed by an injection molding method using a molten thermoplastic elastomer as a material.

  By forming the cylindrical sleeve 21 by the injection molding method, the cylindrical sleeve 21 can be firmly fixed to the stabilizer bar 100 by the welding action of polypropylene and the shrinking action accompanying the improvement of the crystallinity of the polypropylene material. Further, by forming the bush 20 by injection molding, the bush 20 is firmly fixed to the cylindrical sleeve 21 by welding, and the bush 20 is firmly fixed to the bracket 32 by welding. Thus, a structure in which the stabilizer bar 100, the cylindrical sleeve 21, the bush 20 and the bracket 32 are integrated is obtained.

(Modification 1)
5 to 7 are modifications of FIG. 5-7, the attachment parts 40, 50, and 60 are shown. The attachment portions 40, 50, 60 can be applied to the portions of the attachment portions 30, 31 in FIG. In the example of FIG. 5, the cylindrical sleeve 21 is welded to the outer periphery of the stabilizer bar 100, and the bush 41 including four blocks 41 a having a space formed at four locations and having a shape different from that of the block 20 a is the cylindrical sleeve 21. And the inner surface of the bracket 32 are welded. In the example of FIG. 6, the cylindrical sleeve 21 is welded to the outer periphery of the stabilizer bar 100, and a gap 51 is formed at two locations, and the bush 51 including the two blocks 51 a is connected to the outer peripheral surface of the cylindrical sleeve 21 and the bracket 32. It is welded to the inner surface of the.

  In the example of FIG. 7, the cylindrical sleeve 21 is welded to the outer periphery of the stabilizer bar 100, and gaps are formed at three locations, and the bush 61 including three blocks 61 a includes the outer peripheral surface of the cylindrical sleeve 21 and the bracket 32. It is welded to the inner surface of the. Further, the gap for forming the block 61 a does not face the outer peripheral surface of the cylindrical sleeve 21 and the inner surface of the bracket 32, and is formed inside the bush 61. That is, the bush 61 is heat-welded to the entire outer peripheral surface of the cylindrical sleeve 21 and the entire inner surface of the bracket 32 in the injection molding range. For this reason, the fixing strength between the bush 20 and the cylindrical sleeve 21 and the bracket 32 is higher than when the gap faces the outer peripheral surface of the cylindrical sleeve 21 or the inner side surface of the bracket 32.

(Modification 2)
FIG. 8 is a modification of FIG. FIG. 8 shows the attachment portion 70. The attachment portion 70 can be applied to the portions of the attachment portions 30 and 31 in FIG. In this example, the cylindrical sleeve 21 is welded to the outer periphery of the stabilizer bar 100, and a gap 71 is formed at four locations, and the bush 71 including four blocks 71 a includes the outer peripheral surface of the cylindrical sleeve 21 and the inner surface of the bracket 72. It is welded to. The bush 71 is provided so as to fill an inner space having a cylindrical shape of the bracket 72.

  The bracket 72 is provided with a flange 73, and the flange 73 is provided with a bolt hole 74. The flange 73 is fixed by bolts to the chassis of the vehicle body (not shown) using the bolt holes 74.

  Even in this configuration, the stabilizer bar 100, the cylindrical sleeve 21, the bush 71, and the bracket 72 are integrated by welding.

(Modification 3)
9 to 11 are modifications of FIG. 9 to 11 show the attachment portions 80, 90, and 110. The attachment portions 80, 90, 110 can be applied to the portions of the attachment portions 30, 31 in FIG. In the example of FIG. 9, the cylindrical sleeve 21 is welded to the outer periphery of the stabilizer bar 100, and the bush 81 composed of six blocks 81 a with gaps formed at six locations is formed between the outer peripheral surface of the cylindrical sleeve 21 and the bracket 82. It is welded to the inner surface of 83. The bush 81 has a structure in which halved shapes 81b and 81c are welded and integrated.

  In the example of FIG. 10, the cylindrical sleeve 21 is welded to the outer periphery of the stabilizer bar 100, and a gap 91 is formed at six locations, and the bush 91 including four blocks 91 a includes the outer peripheral surface of the cylindrical sleeve 21 and the bracket 92. It is welded to the inner surface of 93. The bush 91 has a structure in which half-shaped 91b and 91c are welded and integrated. In the example of FIG. 11, the cylindrical sleeve 21 is welded to the outer periphery of the stabilizer bar 100, and a gap 111 is formed at three locations, and the bush 111 composed of three blocks 111 a is connected to the outer peripheral surface of the cylindrical sleeve 21 and the bracket 112, It is welded to the inner surface of 113. The bush 111 has a structure in which the half-shaped shapes 111b and 111c are welded and integrated. Since the attachment portions 80, 90, and 110 differ only in the shape and number of blocks, the attachment portion 80 in FIG. 9 will be described below.

  The outer periphery of the bush 81 is sandwiched from above and below by brackets 82 and 83, and the outer periphery of the block 81 a of the bush 81 is welded to the inner surfaces of these brackets 82 and 83. The bracket 82 has a flange 82a, and a bolt hole 82b is formed in the flange 82a. The bracket 83 has a flange 83a, and a bolt hole 83b is formed in the flange 83a. The bolt holes 82b and 83b are used to fix the stabilizer bar 100, the cylindrical sleeve 21, the bush 81, and the brackets 82 and 83 in an unillustrated vehicle frame.

  An example of a process for obtaining the attachment portion 80 will be described. The manufacturing method of the mounting portion 80 will be briefly described. First, the lower half is made, and then the upper half is made. That is, the bracket 82 is disposed in the mold, and the stabilizer bar 100 to which the cylindrical sleeve 21 is welded is disposed as in the case of FIG. In this state, a mold for forming the bush 81c is covered from above and the thermoplastic elastomer in a molten state is injection-molded to form the bush 81c. At this time, the bush 81 c is welded to the inner surface of the bracket 83 and is welded to the outer peripheral surface of the lower half of the cylindrical sleeve 21.

  Next, with the bracket 82 covered from above, the thermoplastic elastomer in a molten state is injection-molded to form the bush 81b. At this time, the bush 81 b is welded to the bush 81 c, and the bush 81 b is welded to the outer peripheral surface of the upper half of the cylindrical sleeve 21 and the inner surface of the bracket 82. Further, by performing injection molding in a state where the brackets 82 and 83 are set in a mold in advance, the portions 81b and 81c can be formed simultaneously. In this case, a bush indicated by reference numeral 81 welded to the inner side surfaces of the brackets 82 and 83 and further welded to the cylindrical sleeve 21 is formed by one injection molding.

(Other)
A small amount of a thermosetting adhesive can be used in combination in order to obtain an adhesive force by welding. In this case, the thermosetting adhesive enters the fine irregularities of the stabilizer bar, cylindrical sleeve, and bracket coating surface and non-coating surface before curing, and then adheres with the anchor effect by thermosetting and solidifying. Force is developed. The thermosetting adhesive is preferably a two-component epoxy adhesive. Further, as the adhesive, a cyanoacrylate-based adhesive or a solvent-diluted rubber adhesive can be used. A small amount of primer may be used in combination. The primer is preferably a chlorinated ethyl acetate solution type.

  Moreover, the space | gap completely enters between adjacent blocks, and the state where adjacent blocks are not contacting at all may be sufficient. The boundary between the blocks in this case is the same as the case where a gap is formed in a state where both sides of adjacent blocks 20a are connected as shown in FIG. In this case, the fixing strength between the bush and the cylindrical sleeve 21 is lower than that in a state where both sides of adjacent blocks 20a are connected as shown in FIG.

Example 1
A structure shown in FIG. 8 was prototyped. In this example, a 14 mmφ rod-shaped steel material was used as the stabilizer bar 100, and a 10 mm-thick aluminum extruded material cut into a length of 30 mm (length in the axial direction) was used as the bracket 72. As the cylindrical sleeve 21, polypropylene having an axial length of 30 mm and a thickness of 2 mm was formed by an injection molding method. The thickness of the bush 71 was 7 mm at the arc portion and 15 mm at the upper portion. The number of blocks 71a of the bush 71 was four. As the thermoplastic elastomer, an olefin-based one was used. In addition, the welded surface of the stabilizer bar was pretreated by shot peening and then pretreated by epoxy coating.

  The resulting olefinic thermoplastic elastomer had a tensile strength at break of 20 MPa, a 100% tensile modulus of elasticity of 4 MPa, and a tensile elongation of 600%.

(Example 2)
A structure shown in FIG. 10 was prototyped. The brackets 92 and 93 were made by pressing a 7 mm thick galvanized plain steel plate. The thickness of the bush 91 was 7 mm at the arc portion. The number of blocks 91a of the bush 91 was four. Further, as the thermoplastic elastomer, a urethane-based one was used. The obtained urethane-based thermoplastic elastomer had a tensile strength at break of 25 MPa, a 100% tensile elastic modulus of 6 MPa, and a tensile elongation of 800%. Others are the same as Example 1.

(Example 3)
The structure shown in FIG. The number of blocks 41a of the bush 41 was four. As the thermoplastic elastomer, an olefin-based one was used. The resulting olefinic thermoplastic elastomer had a tensile strength at break of 20 MPa, a 100% tensile modulus of elasticity of 4 MPa, and a tensile elongation of 600%. Others are the same as Example 1.

Example 4
A structure shown in FIG. 9 was prototyped. The brackets 82 and 83 were obtained by pressing a galvanized plain steel plate having a thickness of 7 mm. As the cylindrical sleeve 21, a polyacetal having an axial length of 30 mm and a thickness of 2 mm was formed by an injection molding method. The thickness of the bush 81 was 7 mm at the arc portion. The number of blocks 81a of the bush 81 was six. Further, as the thermoplastic elastomer, a urethane-based one was used. The obtained urethane-based thermoplastic elastomer had a tensile strength at break of 25 MPa, a 100% tensile elastic modulus of 6 MPa, and a tensile elongation of 800%. Others are the same as Example 1.

(Comparative Example 1)
FIG. 12 is a cross-sectional view showing an outline of a conventional attachment portion. In the embodiment shown in FIG. 12, natural rubber (tensile breaking strength: 20 MPa, 100% tensile elastic modulus: 5 MPa, tensile elongation: 400%) is used as the bush 220, and the natural rubber bush 220 is connected to the stabilizer bar 100 and the bracket 272. It was set as the structure adhere | attached on the epoxy adhesive. In addition, the primer treatment was previously performed on the adhesion surface between the stabilizer bar 100 and the bracket 272. In addition, the bracket 272 was made by pressing aluminum having a thickness of 10 mm.

(Comparative Example 2)
FIG. 13 is a cross-sectional view showing an outline of a conventional attachment portion. In the embodiment shown in FIG. 13, natural rubber (tensile breaking strength: 20 MPa, 100% tensile elastic modulus: 5 MPa, tensile elongation: 400%) is used as the bush 220, and the natural rubber bush 220 is connected to the stabilizer bar 100 and the bracket 282. , 283 with an epoxy adhesive. In addition, the primer surface was previously applied to the adhesion surface between the stabilizer bar 100 and the brackets 282 and 283. In addition, the brackets 282 and 283 are made by pressing a 7 mm thick galvanized plain steel plate.

(Comparative Example 3)
FIG. 14 is a cross-sectional view showing an outline of a conventional attachment portion. In the embodiment shown in FIG. 14, natural rubber (tensile breaking strength: 20 MPa, 100% tensile elastic modulus: 5 MPa, tensile elongation: 400%) is used as the bushing 220, and the natural rubber bushing 220 is connected to the stabilizer bar 100 and the bracket 232. In addition, the structure was bonded with an epoxy adhesive. The adhesive surface between the stabilizer bar 100 and the bracket 232 was previously subjected to a primer treatment to which primer coating was applied. In addition, the bracket 232 was made by pressing aluminum having a thickness of 10 mm.

(Comparative Example 4)
A structure shown in FIG. 14 was prototyped. In this example, the bush 220 is fixed to the stabilizer bar 100 and the bracket 232 by heat welding. The bracket 232 was made by pressing aluminum having a thickness of 10 mm. The thickness of the bush 20 was 7 mm at the arc portion and 15 mm at the upper portion. As the thermoplastic elastomer, an olefin-based one was used. The resulting olefinic thermoplastic elastomer had a tensile strength at break of 20 MPa, a 100% tensile modulus of elasticity of 4 MPa, and a tensile elongation of 600%. The welded surface of the stabilizer bar was subjected to a blasting treatment by shot peening in advance and then a pretreatment by epoxy coating.

(Result of destructive test)
A destructive test was performed on the obtained sample. This destructive test is a test in which the bracket is fixed, the stabilizer bar 100 is twisted in an arbitrary fixed direction with respect to the axis, and the rotation angle at which the destructive occurs is measured. And how many times the twist occurred during the “stabilizer bar / bush” or from the “bush” of the “stabilizer bar / bush / bracket” or between the “bush / bracket” and how many times it was twisted By the way, we evaluated whether destruction occurred.

  “Table 1” summarizes the examples. “Table 2” summarizes the comparative examples.

  As is clear from Tables 1 and 2, when natural rubber is used for the bush and this bush is fixed to the stabilizer bar and bracket with an adhesive, the fracture angle is relatively small, and the fracture occurs at the interface where it is adhered. ing. This indicates that the adhesive strength between the bush and the stabilizer bar and between the bush and the bracket is low in adhesion compared to welding using the cylindrical sleeve + thermoplastic elastomer.

  In addition, as shown in Comparative Examples 1 to 3 in Table 2, when bushing 220 is welded as shown in Comparative Example 4 in Table 2, compared to the case where fracture occurs at the bonded bar interface or bracket interface. Since it occurs in the thermoplastic elastomer layer constituting the bush, superiority is shown in terms of fixing strength. Furthermore, compared with the case of the comparative example 4 of Table 2, Examples 1-4 of Table 1 have a large destruction angle. This indicates that the bush is easily deformed by reducing the burden on the bush by providing a gap in the bush in addition to the welding using the cylindrical sleeve + thermoplastic elastomer.

  As described above, the structure of the present embodiment can be manufactured by injection molding, and therefore does not require a complicated construction method. And, as is apparent from the above destructive test, it occurs in the thermoplastic elastomer layer that constitutes the bush before the failure occurs at the welded interface. This indicates the high adhesion strength of the interface.

  This characteristic is due to repeated twisting and axial force, creating a gap between the bushing and the mating member, which gradually expands, causing abnormal noise and instability of the stabilizer effect. This is effective in suppressing the gradually increasing phenomenon.

  The present invention can be used for a stabilizer device for a vehicle.

  DESCRIPTION OF SYMBOLS 1 ... Stabilizer apparatus, 2 ... Tire, 3 ... Suspension apparatus, 4 ... Tire, 11 ... Stabil link, 12 ... Movable member, 13 ... Arm, 20 ... Bush, 20a ... Block, 21 ... Cylindrical sleeve (thermoplastic plastic), DESCRIPTION OF SYMBOLS 30 ... Mounting part, 31 ... Mounting part, 32 ... Bracket, 33 ... Flange, 34 ... Bolt hole, 100 ... Stabilizer bar, 131 ... Mold, 132 ... Upper pressing mold, 134 ... Space in mold, 135 ... Injection hole, 136 ... Air vent hole.

Claims (8)

Stabilizer bar,
A cylindrical thermoplastic plastic fixed to the outer periphery of the stabilizer bar;
A bracket fixed to the vehicle body,
A bush formed of a thermoplastic elastomer that is bridged between the outer peripheral surface of the plastic and the inner side surface of the bracket and that has voids formed at two or more locations, and is fixed to the plastic and the bracket by thermal welding. A stabilizer device characterized by comprising. When the stabilizer bar is rotated relative to the bracket around its axis,
The bush is material destroyed when the rotation angle of rotation is 60 ° or more,
2. The stabilizer device according to claim 1, wherein a peeling failure does not occur at an interface between the plastic and the bracket of the bush when the material failure occurs. 3.   3. The stabilizer device according to claim 1, wherein a coefficient of dynamic friction of faces facing each other with the gap interposed therebetween is 0.4 or less.   The stabilizer device according to any one of claims 1 to 3, wherein the thermoplastic plastic is a crystalline thermoplastic plastic. Placing a bracket having a predetermined length in the mold in the mold and a stabilizer bar having a cylindrical thermoplastic plastic fixed to the outer periphery;
The molten thermoplastic elastomer is injected into the mold, thermally welded to the bracket, and thermally welded to the plastic, and is bridged between the outer peripheral surface of the plastic and the inner surface of the bracket at two or more locations. Forming a bush in which a gap is formed by an injection molding method. When the stabilizer bar is rotated relative to the bracket around its axis,
The bush is material destroyed when the rotation angle of rotation is 60 ° or more,
The method for manufacturing a stabilizer device according to claim 5, wherein no peeling failure occurs at an interface between the plastic and the bracket of the bush when the material failure occurs.   The method for manufacturing a stabilizer device according to claim 5, wherein a coefficient of dynamic friction of faces facing each other with the gap interposed therebetween is formed to be 0.4 or less. The thermoplastic plastic is a crystalline thermoplastic plastic;
8. The method according to claim 5, further comprising a step of fixing the thermoplastic plastic to the stabilizer bar by shrinking while improving the crystallinity of the thermoplastic plastic by cooling. A method for manufacturing the stabilizer device according to claim 1.

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